Mechanized automatic harvesting machines are widely used in large-scale farming operations in the grain farming regions of the world, particularly in the United States and Canada. These machines permit a significant reduction of the man hours required to harvest a crop, and allow a single farmer to farm large acreages, which were impossible in the labor-intensive farming industry at the turn of the century in the United States and, even today, in many parts of the world.
Although large-scale mechanized farming and harvesting operations are well known in conjunction with grain farming, such mechanized farming has eluded vegetable farmers in most cases. Most vegetables are harvested by hand. This requires a large number of workers per acre of crop to accomplish the harvesting, since the crop generally has only a very short time (a matter of a very few days) in most cases, when it is at its peak for harvesting. As labor costs continuously increase, the cost of vegetables produced on such farms continues to rise accordingly.
Some progress has been made to alleviate the high cost of labor in harvesting vegetable crops. In particular, with respect to the harvesting of peas and beans, mechanical harvesting machines have been developed, which fairly effectively permit the harvesting of a crop. One such machine, directed to a pea picker, is disclosed in the patent to Bell U.S. Pat. No. 2,374,162. The machine of Bell uses a combination helix and beater-fingers all located on a single rotating shaft to pick peas or beans, and the like. The plants are gathered up by the input end of the helix, which picks them up and tears them apart, and supplies them to a cutter which cuts them off. Beaters, located in the next section of the machine, then knock off the peas or beans. In the case of peas, the beaters strike the pods hard enough to break the pods open; so that the peas fall out. The peas or beans, which are harvested by this machine, then drop onto a conveyer beneath it. The remainder of the plants then are moved upwardly and outwardly through another part of the machine, from which they are disposed. The machine of this patent, however, destroys the plants bearing the crops to be harvested; so that multiple harvesting of the same plants cannot be effected.
A somewhat different approach is disclosed in the patent to Esch U.S. Pat. No. 2,874,528. This patent is directed to a bean picker which employs vertically rotating helixes to lift the bean plants upwardly and snap the beans off at the top end of travel with a hook located at the top of each of the helixes. Multiple rotating helixes are employed, and considerable damage to the plants occurs.
Another approach is disclosed in the patent to Morgan U.S. Pat. No. 3,473,304. This patent is directed to a vegetable picker which has a slot for guiding the plant into a location next to a large helix. The helix serves to compact all of the leaves and vegetables into a rather tight bunch. The plant is moved to a location adjacent a counter-rotating brush, which strips off the beans, peas or other vegetables from the plant. The helix itself is not the picking element, but merely locates the crops adjacent the picking brush. Although the machine of Morgan is designed with an intent to preserve the plant, large numbers of leaves necessarily are stripped from the plant during the contact with the stripping brush. In addition, branches and stems of the plant are frequently broken. As a result, the condition of the plant after the harvesting machine has passed over it, is substantially weakened. In many cases, the plant is damaged to such an extent that it is incapable of producing a second crop.
Although the machines of the patents described above have been used with some degree of success for picking beans and peas, mechanized picking machines for peppers (such and green and red chiles, bell peppers, and the like) and tomatoes, capable of harvesting the crop without damaging it or destroying the plant, or both, had not been developed until the machine disclosed in Rodriguez U.S. Pat. No. 4,196,570. The machine of that patent employs a picking mechanism mounted on a central rotatable shaft, which is located above the row of plants to be picked. The shaft is longitudinally aligned parallel with the row. The shaft has a helical guide attached to it, with the spacing between adjacent turns of the helix selected to be equal to the spacing between each plant in the row of plants to be picked. A number of arcuate picking elements are mounted on the helix, and extend between the outer turns of the helix and the shaft to engage the peppers or other vegetables on the plant to pick them as the machine is moved over the row of plants. This machine has proved very effective for picking peppers with minimum damage to the plant. As a consequence, the plant can be used to produce subsequent crops for harvest, resulting in substantial savings.
A disadvantage of the machine of Rodriguez U.S. Pat. No. 4,196,570, however, is that the rotation speed of the helix and the location of each turn of the helix must be carefully synchronized with the movement of the machine and the spacing of the plants to avoid tearing up or uprooting any of the plants in the row to be harvested. If the helix rotation is out of synchronization with the movement of the machine over the row, or if the plant-to-plant spacing is different from the turn-to-turn spacing of the helix, substantial damage to the plants can occur. Thus, it is necessary for the design of the machine to be precisely related to the plant spacing, and it is also necessary for the operator of the machine to exercise skill and care in threading the machine through the row of plants to effect the picking operation.
It is desirable to harvest crops from pepper plants and tomato plants and the like with a mechanized harvesting machine which overcomes the disadvantages of the prior art mentioned above. Such a machine ideally should harvest the crop without damage to the plants, and also without damaging the crop, and should leave the plant in a strong and healthy condition after the harvesting operation; so that the plant can be used to produce subsequent crops. In addition, it is desirable that such a machine may be universal in its application to the harvesting of a crop, and not require any particular synchronization on the part of operator to effect the harvesting operation.